Complete Denture Short Notes

Vestibuloplasty

Answer:

Vestibuloplasty is a surgical procedure designed to restore alveolar ridge heights by lowering muscle attachment on the buccal, labial, and lingual aspects of the residual ridges.

Vestibuloplasty Procedures

• Transpositional flap vestibulopathy for anterior mandible
• Maxillary submucosal vestibuloplasty
• The floor of the mouth lowering
• Epithelial graft vestibulopathy
• Secondary epithelialization procedures.

Vestibuloplasty Transpositional Flap Vestibuloplasty/Lip Switch

• Indication—To increase the vestibular depth in the anterior mandible when there is a 15 mm bone height.
• Procedure—A submucosal dissection from the inner aspect of the lower lip to the mucogingival junction followed by a subperiosteal dissection to replace the muscle and soft tissue attachments to the desired vestibular depth.
• A periosteal incision is made near the crest of the ridge and the periosteum is lifted off the bone and it is sutured to the raw lip bed. The mucosal flap is adapted to the exposed bone to the depth of the vestibule and fixed with sutures or stents.

Vestibuloplasty Maxillary Submucosal Vestibuloplasty (described by Mcintosh and Obwegeiser)

Indication—When there is good underlying bone but not available due to high frenal and muscle attachments. To ensure the depth a mouth mirror is placed in the vestibule and checked for shortening of the lip, if the lip does not shorten then the case can be considered for submucosal vestibuloplasty.

Vestibuloplasty Procedure: A vertical midline incision is made on the anterior maxilla and a subperiosteal tunnel is created by dissecting the tissue away from the periosteum. The intervening submucosal tissue is then repositioned superiorly and it is secured in place with a postoperative stent.

The stent is worn for one week. The healing period is 3 weeks. In the meantime, a new prosthesis is fabricated to the new vestibular depth and inserted to prevent relapse.

Vestibuloplasty The floor of the Mouth Lowering

Procedure: Crestal incision is made lingual to the attached gingiva and subperiosteal dissection
is done to the desired depth and sutured to the periosteum. The denuded periosteum is allowed to heal by secondary epithelialization or an epithelial graft is placed.

Vestibuloplasty with Split Thickness Skin or Palatal Mucosal Graft

Vestibuloplasty with grafting increases the sulcus depth and the amount of attached tissue. There is very little postoperative loss of vestibular depth.

Vestibuloplasty Procedure: The skin graft is harvested from the caudal part of the iliac crest or inner aspect of the thigh with a dermatome. Intraorally an incision is made at the mucogingival junction and a subperiosteal dissection is done.

The detached tissue is sutured to the depth of the periosteum and the graft is maintained by a stent held by circum mandibular wiring.

 Leon William Classification (1914)

Answer:

It was classified by Leon William to aid in the selection of anterior teeth for complete denture prosthesis.

• He claimed that the shape of the upper central incisor bears a definite relationship to the shape of the face.

Leon William Classification  Classification

• Square
• Tapering
• Ovoid.

Leon William Classification  Locating the teeth’ shape

If one of these teeth were enlarged and the incisal edge placed above the brows with the neck of the tooth on the chin, then the outline of the tooth would coincide with that of the face. Two lines, one on either side of the face, running about 2.5 cm in front of the tragus of the ear.

Leon William Classification  Classification Of Patients

A complete denture prosthesis patient can present themselves to the dentist in any of the three classes stated below:

1. Those whose upper anterior teeth are still remaining but will soon be extracted due to various reasons. This group can be considered for Immediate Dentures.
2. Those who are already complete denture wearers. The period of time these patients wore complete dentures are important as longer the period, the patient and his immediate circle of relations and friends would have been satisfied with the appearance of the dentures. When
   remaking dentures for these patients it is not advisable to make very marked alterations in an individual’s appearance.
3. The third category of patients are those who present for the first time edentulous and requiring dentures, who have lost their dentures, or who are dissatisfied with the existing dentures.

The Leon William classification for the selection of anterior teeth will be considered depending on the:

• Shape
• Size
• Color

Leon William Classification  Shape

From the observation of many patients, it was found that there was some relationship between the shape of the edentulous upper arch and the upper teeth.

Leon William Classification  The Findings Were That

1. A V-shaped arch is associated with incisors that are narrower at the neck than at the incisal edge.
2. A squarish arch with almost parallel-sided incisors.
3. A round arch with ovoid teeth.

Instructions to complete denture patient

Answer:

They should be educated not to make comparisons of chewing, speech patterns or compare to the experience of other denture wearers.

1. Adaptability to new dentures:
   • Younger the patient, the more adaptable to dentures.
2. Appearance with new dentures:
   • Appearance with new dentures will become more natural with time as initially, the dentures will feel strange and bulky in the mouth.
   • Patients should be instructed to refrain from exhibiting their dentures until they are more confident or they may become unfairly critical of the dentures.
3. Mastication with new dentures:
   • As learning to chew with new dentures requires at least 6 to 8 weeks patients are made aware that this learning period is to be expected and the muscles of the tongue, cheeks, and lips must be trained to maintain the dentures in position on the residual ridges during mastication.
   • Patients are instructed to chew soft food cut into small pieces and the chewing is best done on both sides of the mouth at the same time.
4. Position of the tongue:
   • The ideal position is to position the tongue on the lingual surfaces of the lower anterior teeth. This will help develop stability for the lower denture
5. Speaking with new dentures:
   • Initially, the additional bulk over the palate and the linguogingival border of the anterior teeth would cause a speech defect, especially in the production of “S” sounds. But as the tongue is very adaptable it doesn’t cause, phonetic changes that are too great to be readily compensated.
6. Oral hygiene with dentures
   • Patients must be convinced of the importance of maintaining good oral hygiene. Plaque,
     stain and calculus accumulate on dentures and oral mucosa of edentulous patients.
   • Patients should be instructed to rinse their dentures and their mouths after meals. Leaving the dentures in the cleanser (Kleenite) overnight is needed for the effective killing of micro-organisms and removal of all stains.
   • After the dentures are removed from the soaking cleanser, they should be brushed gently with a soft brush and rinsed thoroughly.
7. Preserving the residual ridges:
   • Patients must be cautioned not to do any adjustments to the dentures.
   • Patients should be told that dentures must be left out of the mouth at night to provide needed rest from the stresses they create on the residual ridges. When dentures are left out of the mouth, they should be placed in a container filled with water to prevent drying and possible dimensional changes.
8. Periodic recall of patients:
   • As the tissues supporting dentures change with time, depending on local and general factors all edentulous patients should be examined by a dentist at least once a year and should be placed on a recall list.
9. Educational material for patients
   • Written instructions or other formal educational material is helpful to educate the patient and to follow instructions without a doubt.

notes on.

1. Christensen’s phenomenon
2. Buccal corridor
1. Christensen’s phenomenon
Answer:

Protrusive movement of the mandible which is created by the downward and forward movement of the condyles riding along the articular eminence removes the posterior teeth from contact in the natural dentition.

• This shifts the occlusal pressure to premolars and is known as Christensen’s phenomenon.
• If complete dentures are not balanced in the protrusive excursion, the resulting posterior disocclusion and pressure in the premolar area can cause dislodgement of the denture bases. A fully balanced denture will negate this phenomenon.

Christensen’s Phenomenon Sagittal Christensen’s Phenomenon

The Sagittal Christensen phenomenon means that when the patient protrudes, a reversely open, wedge-shaped gap occurs at the molars.

Christensen’s Phenomenon Transverse Christensen Phenomenon

The Transverse Christensen phenomenon means that when the patient performs laterotrusion, on the non-working side, a reversely open, wedge-shaped gap occurs at the molars. The same occurs during canine guidance in natural teeth.

Christensen’s phenomenon Buccal corridor

• The area between the corners of the mouth during smile formation and the buccal surfaces of the maxillary teeth (particularly the bicuspids and molars) form a space known as the buccal corridor.
• The greater and more pronounced this negative space becomes, the more these posterior teeth are concealed, restricting the full breadth of the smile.
• A full and symmetric buccal corridor is an important element of an esthetic smile. The buccal corridor should not be completely eliminated because a hint of negative space imparts depth to the smile.

Christensen’s phenomenon Factors Influencing the Appearance of the Buccal Corridor

• Width of the smile and the maxillary arch
• Tonicity of facial muscles
• Individual smiling characteristics
• The position of the labial surfaces of the maxillary bicuspids
• The predominance of the cuspids, particularly at the distal facial line angle
• Any discrepancy between the value of the bicuspids and the six anterior teeth
• This negative space is often accentuated when smile rejuvenation is limited to the maxillary six anterior teeth
• When the hue and value of newly restored teeth do not blend with the untreated teeth, an unwanted exaggeration of the sense of depth, darkness, and prominence of the buccal corridor occurs.

Lingualized occlusion (Alfred Gysi in 1927)

Answer:

Lingualized occlusion uses the maxillary lingual cusp as the dominant functional element, occluding against the corresponding position of the mandibular tooth.

Lingualized occlusion Types

• Balanced lingualized occlusion
• Nonbalanced lingualized occlusion: This type of occlusion involves the use of a large upper palatal cusp against a wide lower central fossa. In this scheme, the buccal cusps of the upper and lower teeth do not contact each other.

Lingualized occlusion Advantages

1. Reduces the damaging forces while maintaining chewing efficiency.
2. Allows easier accommodation to unpredictable changes taking place in the basal seat because it provides an area of closure.
3. Simplicity.
4. Flexibility.

Lingualized Occlusion Incorporation Of Lingualized Occlusion In Arrangement

1. The height of anterior teeth is determined by aesthetics and phonetics.
2. Buccolingually the lingual cusps of the mandibular teeth are located within a line drawn from the distal of the canine to the buccal and lingual sides of the retromolar pad.
3. A 20° template is used to set a shallow anteroposterior and mediolateral compensatory curve.
4. The maxillary posterior teeth are set with the palatal cusp in the central groove of the mandibular tooth. The maxillary buccal cusp is elevated off the occlusal plane more as one moves posteriorly.
5. Sometimes the mandibular fossa and the inclines of the maxillary palatal cusp need selective grinding to accommodate uniform contacts in working, balancing, and protrusive movements.
6. Payne proposed the use of 30° anatomical teeth which were reshaped to obtain lingual occlusion.

Lingualized Occlusion Myerson’S Lingualized Integration (MLI)

• Myerson proposed specialized tooth molds namely control contact (CC) mold and maximum contact (MC) mold.
• The remaining teeth are common for both these molds.
• MC molds are used for patients who can reproduce the accurate centric position
• CC mold for patients with variations in centric position. The ‘MC’ mold maxillary posteriors have taller cusps with anatomical appearance compared to the ‘CC mold.
• These teeth provide maximal intercuspation and a natural and pleasing appearance.

Lingualized occlusion Non-Balanced Lingualized Occlusion (Payne)

Here the arrangement is the same as for the anatomical form except that Maxillary teeth with blunt cusp and mandibular teeth with limited occlusal anatomy is used to allow more anteroposterior
freedom.

Neutrocentric concept

Answer:

The term eurocentric concept of occlusion denotes any occlusion that eliminates anteroposterior or mediolateral inclines of the teeth and directs the forces of occlusion to the posterior teeth.

Neutrocentric concept DeVan’s “eurocentric concepts (1954)

1. The teeth should have flat occlusal surfaces.
2. The teeth should have flat planes in all directions with no inclination to the underlying denture foundation.
3. Balance was not required as the resulting inclines would create instability of the dentures.

Neutrocentric concept Incorporating Neutrocentric Concept

1. The anteroposterior plane of occlusion should be parallel with the plane of the denture foundation.
2. The teeth are arranged on a flat plane, which does not form compensating curves.
3. In a mediolateral direction, the teeth are set flat with no medial or lateral inclination.
4. The posterior teeth are placed in as mediolateral a relation in reference to the residual ridge as the tongue function will allow.
5. Articulator settings:
   • As incising is avoided with no cusps projecting above or below the occlusal plane, the horizontal condylar guidance can be set at zero.
   • As the teeth are not arranged in balancing contacts in eccentric relations the lateral condylar guidance of the articulator can be set at zero.
   • The condylar elements are secured to function in the opening and closing movements.

Eurocentric Concept Factors In Tooth Selection

1. Zero-degree tooth.
2. The buccolingual width of the teeth is reduced.
3. The number of teeth is reduced to direct the forces in the molar and bicuspid areas.
4. The tooth is not placed on the ridge incline in the second molar area.

Neutrocentric Concept Patient Instruction

Not to incise with the incisors.

Try-in is done for the waxed dentures in the patient’s mouth before finishing them to verify occlusion and other factors.

Factors To Check At Trial

Factors To Check At Trial Lower Denture

1. Peripheral outline:
2. The Buccal, Labial, Lingual, and Posterior flanges are checked for under-extension and over-extension.
3. Stability
4. Tongue space
5. Height of the occlusal plane.

Factors To Check At Trial Upper Denture

1. Peripheral outline:
   The buccal, labial, and posterior flanges are checked for under-extension and over-extension.
2. Stability
3. Retention (efficiency of posterior palatal seal).

Factors To Check At Trial Both Dentures Together

In occlusion

1. Centric relation
2. The vertical dimension of occlusion
3. Uniform bilateral contact
4. Balanced occlusion
5. Appearance.

Factors To Check At Trial In anterior try in

1. Midline
2. Anterior plane
3. The shape of the teeth
4. Size of the teeth
5. The shade of the teeth
6. Profile and lip form
7. Smile line
8. Approval of appearance by the patient.

Advantages of interim dentures.
Answer:

1. The appearance of the patient without teeth during the complete denture procedure is avoided.
2. The patient can carry on with the social activities as usual.
3. In patients with severe periodontal disease where the need for preservation of residual ridge resorption is more.
4. Immediate dentures with proper exodontic treatment have a minimum of trauma, with less residual ridge resorption.
5. The placement of interim dentures for patients who have been without posterior teeth for a long time can help to attain progressive occlusal adjustment and conditioning lining, to help the basal seat tissues, muscles, and joints return to normal and healthy condition.
6. Occlusal vertical dimension can be altered by grinding or adding acrylic resin to the occlusal surfaces of the teeth when required.
7. For patients with posterior stops prior to extraction, the placement of the interim dentures
   preserves the health of the joints, muscles, and oral physiology and aids the patient in avoiding, edentulous state problems such as diet, speech, and appearance.
8. Interim dentures can be worn during the construction of new dentures and can act as spare dentures later on.
9. Interim dentures are good temporary substitutes and can be worn to maintain the oral tissues during rebasing or repairing of the second dentures.
10. The patient’s vertical dimension and muscle function will be maintained, along with proper lip support and other appearance factors.
11. The cost of the interim denture can be compared with the cost of refitting immediate dentures which usually is necessary during the first year.
    • The gingival and interseptal tissue should be retained to provide good cushioning for the denture. Interim dentures should not be made for patients with numerous and heavy undercuts.
    • Interim dentures are ideally suited for solving the periodontal problem because maximum alveolar contour can be maintained.